Problem: Complete the square to solve for $x$. $x^{2}+6x+9 = 0$
The left side of the equation is already a perfect square trinomial. The coefficient of our $x$ term is $6$ , half of it is $3$ , and squaring it gives us ${9}$ , our constant term. Thus, we can rewrite the left side of the equation as a squared term. $( x + 3 )^2 = 0$ Take the square root of both sides. $x + 3 = 0$ Isolate $x$ to find the solution(s). The solution is: $x = -3$ We already found the completed square: $( x + 3 )^2 = 0$